Facile and Highly RegiospecificSynthesis of 2-Aryl-Substituted Pyrazolidin-3-ones from α,β-Unsaturated <i>N</i>-Acylbenzotriazoles and Arylhydrazines

Abstract

The bis-addition of arylhydrazines to α,β-unsaturated N-acylbenzotriazoles to form heterocyclic compounds was achieved in refluxing THF by using triethylamine as promoter. The reaction was highly regioselective and various 2-aryl-substituted pyrazolidin-3-ones were obtained in moderate to good yields.